Rapid, simple and reliable detection of staphylococcal enterotoxin B (SEB) in food products is a crucial step to ensure food safety and prevent food intoxication and gastrointestinal diseases. Current SEB detection is enzyme-linked immunosorbent assay (ELISA), reverse phase latex agglutination and reverse transcription polymerase chain reaction (RT-PCR). In general, these techniques are either time-consuming or labor intensive because of sample incubation, sample pretreatment, tedious washings and extraction of nucleic acid. In this STTR proposal, we are to demonstrate the feasibility to develop a 'pH-test strip like'product for rapid detection of SEB based on photonic crystal silica nanoparticle-hydrogel. We will, for the first time, incorporate SEB specific antibody into SiO2 colloidal photonic crystal array to form a strip that is sensitively responsive to SEB in solutions. In Phase I, the monodisperse silica nanoparticles will be synthesized and the correspondent colloidal photonic crystal array will be fabricated. In Phase II we will expend the concept to other toxins produced by staphylococcus aureus and develop a series of sensitive, reliable and user-friendly commercial products. PUBLIC HEALTH RELEVANCE: The proposed project has practical applications in toxin diagnostics and is intended to improve the safety and security of the nation's biodefense agent and food supply. The objective of this project is to develop an innovative strip technology for rapid detection of Staphylococcal enterotoxins which is listed in NIAID category A, B and C priority pathogens and toxins. The successful outcome of this research should provide direct economic benefits to food and diagnostics industries and the whole society in terms of biosafety.